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Mozilla like Date validation

Valid date string format according to ISO8601 in Mozilla. The RegEx is suitable for checking text type elements in HTML forms when date type is not supported (like in Safari) *Note: The RegEx does not match Leap years and they will be treated as errors (i.e. the Form submission will not pass)

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Top Regular Expressions

Cheat Sheet

Character classes
. any character except newline
\w \d \s word, digit, whitespace
\W \D \S not word, digit, whitespace
[abc] any of a, b, or c
[^abc] not a, b, or c
[a-g] character between a & g
Anchors
^abc$ start / end of the string
\b word boundary
Escaped characters
\. \* \\ escaped special characters
\t \n \r tab, linefeed, carriage return
\u00A9 unicode escaped ©
Groups & Lookaround
(abc) capture group
\1 backreference to group #1
(?:abc) non-capturing group
(?=abc) positive lookahead
(?!abc) negative lookahead
Quantifiers & Alternation
a* a+ a? 0 or more, 1 or more, 0 or 1
a{5} a{2,} exactly five, two or more
a{1,3} between one & three
a+? a{2,}? match as few as possible
ab|cd match ab or cd